According to tradition internal combustion engines have crankshaft bearings, which are lubricated from the crankcase, for instance by oil-splash lubrication. Regarding crankcase scavenged engines the bearings are usually lubricated by the fuel-oil-mixture in the crankcase. The crankcase seals are located outside the bearings. This means that the bearings are subjected to dirt and residual combustion deposits which could shorten the lifetime. Also, the design of the bearings can affect the crankshaft's mechanical stability regarding bending vibrations. High-speed engines, such as two-stroke engines for chainsaws etc., can achieve, in point of bending vibrations, a critical range of speed. Regarding crankcase scavenged engines also the crankcase compression is affected by the design of the bearings and seals, and consequently the engine power.